1. Field of the Invention
The present invention relates to an ink, in particular, an ink suitable for use in recording on media lacking in ink absorptiveness, and an ink-jet recording method using such an ink and ink-jet instruments applying the ink thereto.
2. Related Background Art
Inks for ink-jet recording apparatus in which a liquid ink is ejected from a nozzle of a head to effect printing include water-based inks in which a dye as a coloring material is dissolved in an aqueous solvent, and solid inks in which a dye is dissolved in a waxy solvent setting at ordinary temperature and ejecting the solid solution from a head in a heat melted state.
Ink-jet recording inks of the ultraviolet-curing type include those using a water-soluble dye as described in Japanese Patent Application Laid-Open No. 5-186725, by which printing on plain paper and regenerated paper can be conducted with ease.
As a method of forming images on a plastic sheet or plate, a sublimable dye is used in an ultraviolet-curing resin as described in Japanese Patent Application Laid-Open No. 52-142516.
The following problems are, however, involved in the prior art.
1. When water-based ink is used in color printing, for example, when printing is conducted with an ink of a first color and then with another ink of a second color after the first ink is dried, the first color ink is redissolved in the second color ink if the dots of the second color ink overlap the dots of the first color ink, whereby bleeding occurs, and the quality of the resulting print is hence deteriorated. PA0 2. Since water-based ink makes good use of the penetrability of the solvent into paper, it takes a lot of time to dry the ink, and moreover images with good rub-off resistance cannot be formed if a plastic is used as the recording medium. Media intended for recording are therefore limited to paper. PA0 3. In the ink in which an ultraviolet-curing resin is mixed with a water-soluble dye, the dye does not bleed if water is applied again to the ink after printing. However, fading of the color of the dye by the irradiation of ultraviolet light is unavoidable. PA0 4. With a solid ink, any recording medium can be applied. However, since a soft material, or a wax is used, printed dots thereof are readily rubbed off even by weak frictional force. In general, inks containing an organic solvent develop a solvent-like odor, and hence present an environmental problem. PA0 5. The ink in which a sublimable dye is used in an ultraviolet-curing resin is required to be heated to 120.degree. C. to 180.degree. C. Therefore, the recording media to be used are limited.